Zoysiagrass plant named `Victoria`

ABSTRACT

A new and distinct variety of Zoysiagrass which has a longer growing season and green color retention in winter and less anthocyanin than the variety `El Toro`.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct variety of Zoysiasp., which is a member of the Gramineae family. The parents of`Victoria`, also referred to herein as `Z88-14` are native to Asia.

The new variety is the result of crossing the Zoysiagrass variety `ElToro` (U.S. Plant Pat. No. 5,845) as the female parent and an unnamedproprietary seedling identified as UC #3 as the male parent. Handpollination was performed under greenhouse conditions and seed wasgerminated under laboratory conditions. Seedlings were individuallycultured in a greenhouse before transplanting into a field forevaluation and selection. The varietal denomination of the new varietyis `Victoria`. The new variety is a sibling of the variety `De Anza`which is the subject of Plant Patent Application Ser. No. 08/181,860,filed Jan. 13, 1994.

Sustained drought conditions in California have additionally increasedthe need for improved warm season turf grass varieties. Zoysiagrassesare well adapted for use under such conditions because of their lowwater use rates and high heat tolerance, however, acceptance has beenlow primarily due to loss of green coloration during the winter monthsas such grasses routinely go into dormancy.

`El Toro` Zoysiagrass is a much faster-growing variety of Zoysiagrassthan others of the species, and it made Zoysiagrass more attractive tocommercial sod producers. However, although `El Toro` exhibits a longergrowing season than previously available commercial Zoysiagrassvarieties, it does not remain green all year and also tends to turnpurple during the onset of winter dormancy. In addition, the leaftexture of `El Toro` is considered to be somewhat coarse. The newvariety is an improvement over Zoysiagrass germplasm available for useas turf grass such as `El Toro` Zoysiagrass.

SUMMARY OF THE INVENTION

The new variety of Zoysiagrass, `Victoria`, exhibits an extended growingseason and longer retention of green coloration during the winter seasonthan presently available commercial Zoysiagrass varieties, including `ElToro`. Under moderate climatic conditions such as coastal areas ofCalifornia, acceptable green color quality can be maintained throughoutthe year. The new variety is vegetatively propagated from sod, plugs,tillers or stolon and rhizome pieces. Asexual propagation by rhizomesand tillers in Riverside County Calif. has established that thecombination of characteristics of the new variety are transmittedthrough succeeding propagations. Seed stability has not been determined.

Comparison to `El Toro`

`Victoria` differs from the Zoysiagrass variety `El Toro` in the lengthof the growing season and in retention of green color during winter. Thenew variety also has narrower leaves and produces a finer-textured turfthan `El Toro` and unlike `El Toro`, it produces substantially no purplepigmentation in leaves, stems or inflorescence.

BRIEF DESCRIPTION OF THE ILLUSTRATIONS

The accompanying illustrations show typical specimens of the vegetativegrowth of the new variety depicted in color as nearly true as it isreasonably possible to make the same in color illustrations of thischaracter.

FIG. 1 shows the turf appearance of the new variety on Oct. 15, 1993;

FIG. 2 shows the color of the new variety in December 1991;

FIG. 3 shows the color of `El Toro` in December 1991;

FIG. 4 shows the appearance of a single leaf of the new variety ascompared to another new variety which is the subject of co-pending U.S.plant patent application Ser. No. 08/181,860, filed Jan. 13, 1994, and`El Toro`;

FIG. 5 depicts the leaf orientation of the same three Zoysiagrass linesidentified in FIG. 4; and

FIG. 6 shows stolons of a new variety also compared with the variety ofthe aforementioned co-pending application and `El Toro` to illustratethe difference in purple pigmentation (anthocyanin) as compared to thevariety `El Toro` on Oct. 15, 1993.

DESCRIPTION OF THE NEW VARIETY

Because of its heritage, the new variety `Z88-14` is a hybrid of threeZoysiagrass species, Z. japonica, Z. matrella and Z. tenuifolia. Itforms a moderately dense turf that spreads by way of tillers, stolonsand rhizomes.

Leaf blades of the new variety are bright green in coloration, nearR.H.S. 138A to B, and range from about 1.9 to about 7.0 cm in length,with an average length of about 3.6 cm. The leaf width ranges from about1.8 to about 3.4 mm with an average leaf width of about 2.7 mm. Theshorter leaves are lanceolate in shape while longer leaves becomelinear. Leaves are rolled in the bud and the ligule is a fringe ofhairs. Auricles are absent.

Stolons of `Victoria` are yellowish green to green in color and stoloninternode length ranges from about 0.8 to about 3.6 cm with an averageinternode length of about 2.2 cm. The stem thickness of internodesranges from about 0.9 to about 1.6 mm with an average thickness of about1.2 mm.

In its inflorescence, `Victoria` exhibits a spike-like raceme rangingfrom about 1.6 to about 2.6 cm in length with an average of about 1.9cm. Spikelets average about 3.0 mm in length with a range of about 2.6to 3.4 mm. The peduncles are green and the spikelets are yellowishgreen, becoming straw-colored when mature.

The new variety, like other Zoysiagrasses, is vegetatively propagablefrom sod, plugs or stolon or rhizome pieces. It performs best in fullsun and is best adapted to warmer climates where heat and drought stressoccur. Near-freezing night temperatures will reduce color quality, andprolonged exposuure to freezing or near freezing temperatures willinduce dormancy. The turf formed by the new cultivar is suitable forsituations requiring a durable, high quality lawn that is tolerant ofheat and drought stress and is resistant to pests. Such applicationswould include home lawns, parks and other public planting areas and golfcourses.

The accompanying illustrations serve to illustrate the distinctivefeatures of the new variety. As can be seen from FIGS. 1-6, `Victoria`,also referred to as `Z88-14` differs from the other new variety `DeAnza` (Z88-8), a sister seedling, compared with `Victoria` and also from`El Toro`. In particular, the absence of purple pigmentation of `Z88-14`is shown in FIG. 5, which is compared with the `El Toro` specimen, whichshows extensive purple pigmentation, and the difference in winter colorfrom `El Toro` can be seen in FIGS. 2 and 3.

To further illustrate the difference between the new variety and `ElToro`, tests were conducted at the University of California at Riversideand the University of California South Coast Field Station (SCFS) atIrvine, Calif., to compare the winter color of Zoysiagrasses. Theresults of these evaluations are shown in Tables I and II. Statisticaldifferences among the cultivars were determined using the Duncan'sMultiple Range Test. Values given in Tables I and II that are followedby the same letters are not significantly different from each other atthe 5% probability level. For these comparisons, plugs of the grasseswere placed on one-foot centers with each replicated three times. Commonmanagement practices were used during the 1991-92 period, and afterestablishment, the grasses were mowed at 3/4-inch height at UC SCPS, and5/8 inch at UC Riverside. The grasses were irrigated as needed based onevapotranspiration from an on-site CIMIS station at both locations andwere fertilized at about 6 pounds nitrogen per 1000 square feet of turfarea. Tables I and II present the fall/winter color of the grasses on aregular basis, at both test sites, from November 1992 through March 1993using a rating system of 1 to 9 with 1 representing dormant turf and 9representing full green color. Also shown are the soil temperatures in°F. at 4 inches depth for each observation date. Normal soiltemperatures at UC SCFS did not go as low as Riverside. Once thetemperatures went below 50° F. (at UC Riverside), `El Toro` exhibitedconsiderable color loss while the new variety continued to haveacceptable green coloration.

                                      TABLE I                                     __________________________________________________________________________    OBSERVATION DATE                                                              __________________________________________________________________________    GRASS 10-26-92                                                                           11-2-92                                                                            11-10-92                                                                           11-16-92                                                                           11-23-92                                                                           11-30-92                                                                           12-14-92                                                                           12-21-92                                                                           12-31-92                        __________________________________________________________________________    `El Toro`                                                                           7.7 bcde                                                                           6.7 cde                                                                            7.0 bcd                                                                            7.0 abcde                                                                          6.3 bcde                                                                           6.0 abcde                                                                          4.0 defg                                                                           4.0 cd                                                                             3.3 cd                          `Z88-8`                                                                             9.0 a                                                                              8.0 a                                                                              8.3 a                                                                              8.3 a                                                                              7.7 a                                                                              7.7 a                                                                              7.3 a                                                                              6.7 a                                                                              6.3 a                           `Z88-14`                                                                            8.7 ab                                                                             7.7 ab                                                                             7.7 abc                                                                            7.3 abcd                                                                           6.7 abcd                                                                           7.7 a                                                                              6.3 abc                                                                            6.0 ab                                                                             5.3 ab                          Avg. soil                                                                           68   68   63   62   61   58   56   53   54                              Temp. (°F.)                                                            __________________________________________________________________________    GRASS      1-4-93                                                                             1-20-93                                                                            1-25-93                                                                            2-1-93                                                                             2-8-93                                                                             2-16-93                                                                            2-22-93                                                                            3-1-93                          __________________________________________________________________________    `El Toro`  3.0 def                                                                            3.3 de                                                                             4.0 fg                                                                             4.3 de                                                                             4.3 e                                                                              5.3 efg                                                                            6.0 cde                                                                            5.7 bcd                         `Z88-8`    6.3 a                                                                              7.0 ab                                                                             7.3 ab                                                                             7.7 ab                                                                             7.0 ab                                                                             8.0 ab                                                                             8.0 a                                                                              7.7 a                           `Z88-14`   5.3 ab                                                                             6.0 b                                                                              6.0 cd                                                                             6.7 bc                                                                             5.7 cd                                                                             6.3 cde                                                                            6.9 abcd                                                                           6.5 abc                         Avg. soil  N/A  56   57   56   57   58   58   55                              temp. (°F.)                                                            __________________________________________________________________________

                                      TABLE II                                    __________________________________________________________________________    OBSERVATION DATE                                                              __________________________________________________________________________    GRASS 11-4-92                                                                             11-13-92                                                                           11-20-92                                                                            11-26-92                                                                            12-4-92                                                                            12-14-92                                                                            12-21-92                                                                           12-31-92                         __________________________________________________________________________    `El Toro`                                                                           9.0 a 8.7 ab                                                                             8.0 a 7.3 ab                                                                              6.7 bcde                                                                           4.7 def                                                                             3.0 ef                                                                             1.7 ef                           `Z88-8`                                                                             9.0 a 9.0 a                                                                              8.0 a 7.7 ab                                                                              8.0 a                                                                              6.3 abc                                                                             5.7 a                                                                              5.7 a                            `Z88-14`                                                                            8.7 ab                                                                              8.7 ab                                                                             7.7 ab                                                                              7.7 ab                                                                              7.7 ab                                                                             6.7 ab                                                                              5.3 a                                                                              5.0 ab                           Avg. soil                                                                           64    58   58    52    50   52    49   50                               temp. (°F.)                                                            __________________________________________________________________________    GRASS 1-8-93                                                                             1-13-93                                                                            1-20-93                                                                            1-25-93                                                                            2-5-93                                                                             2-12-93                                                                            2-17-93                                                                            2-24-93                                                                            3-3-93                          __________________________________________________________________________    `El Toro`                                                                           2.0 cd                                                                             1.0 d                                                                              2.0 ef                                                                             2.3 de                                                                             2.7 gh                                                                             5.0 de                                                                             4.7 cd                                                                             5.0 ef                                                                             6.0 cdef                        `Z88-8`                                                                             4.3 a                                                                              4.3 a                                                                              5.7 a                                                                              7.0 a                                                                              7.0 a                                                                              7.0 a                                                                              7.0 a                                                                              7.3 ab                                                                             7.7 a                           `Z88-14`                                                                            4.3 a                                                                              4.3 a                                                                              5.3 a                                                                              6.7 ab                                                                             6.0 bc                                                                             6.3 abc                                                                            6.7 ab                                                                             7.3 ab                                                                             7.0 abc                         Avg. soil                                                                           49   52   53   53   55   56   56   55   55                              temp. (°F.)                                                            __________________________________________________________________________

Establishment Rate

Regarding establishment rate, it was found that `El Toro` was thefastest to cover the soil surface with 70% coverage recorded five monthsfollowing establishment and 100% coverage 10 months followingestablishment. In comparison, `De Anza`, referred to as Z88-8, providedabout 57% coverage after 10 months and `Victoria`, referred to asZ88-14, provided about 34% coverage in the same time period. `De Anza`gave 92% coverage after 10 months and complete coverage 12 monthsfollowing establishment; `Victoria` gave nearly 60% coverage after 10months and provided 100% coverage after 13 months. In comparison toother commercially available cultivars, `De Anza` is quicker toestablish than `Emerald`, `Belair` and `Meyer`; `Victoria` was equal inestablishment rate to `Emerald` but faster than `Belair` and `Meyer`.

Consistently, winter color retention is greatest for `De Anza` and`Victoria` zoysiagrass. As an example, in mid-January during the winterof 1991-1992, on a rating scale of 1-9 with 9 representing deep greencolor and 1 representing dormant, tan or light-brown color, `De Anza`scored a 5.6, `Victoria` a 6.0 and `El Toro` a 2.2. Of the othercommercially available cultivars, `Emerald` scored 2.2 and `Belair` and`Meyer` scored a 1.0.

Other Comparisons

Leaf texture was observed in Summer, 1990 by measuring the leaf bladewidths at the collar in mm. `De Anza` and `Victoria` were characterizedas having an intermediate blade width (on a scale of coarse,intermediate and fine) with blade widths being about 2.72 and about 2.79mm respectively. `El Toro` was coarse with an average width of 3.41 mm;`Emerald` was fine textured with a width of 2.25 mm; `Meyer` and`Belair` both coarse textured with widths of 3.29 and 4.23 mmrespectively.

The amount of seedhead expression was documented throughout the summerof 1990. `De Anza`, `Victoria` and `El Toro` produced more seedheadsthan did the commercially available cultivars `Emerald`, `Belair` and`Meyer`. Utilizing a low, medium and high rating system that was basedon number of seedheads per square meter, `De Anza`, `Victoria` and `ElToro` were rated high and `Emerald`, `Belair` and `Meyer` were ratedlow.

All recording of turfgrass quality was also summarized in a low, mediumand high category by cultivar. `Victoria` was in the high category aswas `Emerald`; `De Anza` and `El Toro` were medium in overall qualityranking; and `Meyer` and `Belair` were in the low rank.

Similarly, `Victoria` had the highest ranking for uniformity ofturfgrass sward; `De Anza`, `El Toro` and `Emerald` were of mediumranking; and `Belair` and `Meyer` were rated low.

Leaf blade stiffness was on a 1 to 3 rating system with 1 representing astiff blade and 3 representing a softer, less stiff blade, `Victoria`was characterized as having a soft leaf blade; El Toro, `Meyer` and`Emerald` were rated intermediate with a score of 2; and `De Anza` and`Belair` were noted to have a stiff blade that characterized thecultivar.

Sod Density and Thatch Accumulation

Sod density was determined in July, 1994 at the University ofCalifornia, Riverside Turfgrass Research Facility and at the Universityof California South Coast Research and Extension Center with densitybeing defined as the number of tillers per unit area and reported on alow to high density scale. `De Anza`, `Victoria`, `El Toro` and `Meyer`were characterized as being of moderate density; `Belair` was lowdensity; and `Emerald` was a high density cultivar. Thatch depthmeasurements taken at the University of California Turfgrass ResearchFacility in July, 1994, documented, in mm of thatch depth, that`Emerald` produced the greatest depth of thatch (25.0 mm); `Meyer`,`Belair` and `Victoria` produced an intermediate thatch depth (18.0,15.0 and 14.0 mm respectively); and `El Toro` and `De Anza` produced thelowest amount of thatch (11.67 and 10.33 mm respectively).

`Victoria` Botanical Description

The grass is a low-growing, perennial, attractive turfgrass that forms amoderately dense sward and spreads by tillers, rhizomes and stolons. Thecolor is identified from The Royal Horticultural Society Colour Chart(R.H.S. Chart) as near 139 C.

Leaf blades are flat and range from about 1.9 to about 7.0 cm in lengthwith an average length of about 3.6 cm. Leaf widths range from about 1.8to about 3.4 mm with an average width of about 2.7 mm. Shorter leavesare lanceolate in shape, while the longer leaves become linear. Leavesare rolled in the bud. The ligule is ciliate with no hairs near theligule nor to the sides of the ligule; auricles are absent. Stolon coloris near 145 C. Stolon internode length ranges from about 0.8 to about3.6 cm and averages about 2.2 cm. Stem thickness of the internodesranges from about 0.9 to about 1.6 mm with an average of about 1.2 mm.

The inflorescence is a spikelike raceme ranging from about 1.6 to about2.6 cm in length with an average length of about 1.9 cm. Culm heightaverage about 14 cm. Spikelets are one-flowered, appressed against arachis and on a pedicel that ranges from about 1.3 to about 1.9 mm longwith an average length of about 1.7 mm. A spikelet with anthers andstigma exerted have a color of near 150 B; mature spikelets are near 19B. Spikelets are shiny in both instances. Glumes are sharply pointed byawnless.

It is evident from the foregoing that the new variety retains greencoloration for a longer period of time than `El Toro` and is, therefore,more desirable as a turf grass in geographical areas favoring its use.

I claim:
 1. A new and distinct variety of Zoysiagrass named `Victoria`,substantially as described and illustrated, which has a longer growingseason and green color retention in winter than the variety `El Toro`,and substantially no purple pigmentation.